Recent years have seen an increase in efforts to develop and implement unconventional computation, that is, non-semiconductor-based computation. These efforts are motivated in part by a breakdown of Moore's law resulting in a slowdown in the rate of increase of computational power of conventional computers, i.e. semiconductor based computers. Some of these efforts are directed at optical computation. That is to say, computation based on manipulation of light, typically lasers, rather than electronic currents as in semiconductor-based computation.